CM 2502 E-Business Mobile Services
Mobile Services Desktop restrictions Mobile technologies Bluetooth WAP Summary
Desktop restrictions Internet opens up access to millions of sites Browser can walk down virtual high street Massive opportunities for opening new markets through e-business BUT l Internet access through a fixed device (PC)
Mobility and access If we can access the internet without using fixed devices; information can be provided in many environments l information can be more current l e-business market could be extended further l How do we mobilise the internet?
Bluetooth short range, wireless link allows ad-hoc connections between; l l l mobile phone portable computer printer mouse headset low power radio, 10 -100 m range max 2. 4 GHz licence-free, frequency-hopping to avoid interference
Bluetooth Cellular (GPRS, 3 G) Packet Data Infrastructure Applications: Vo. IP, browsing, multimedia Bluetooth Addresses connectivity and convenience issues for wireless data Internet
Wireless Application Protocol addresses issues higher up the protocol stack data links on wireless networks are lower than wired networks l radio spectrum (bandwidth) limited internet applications not designed with wireless links in mind wireless links less reliable
Wireless Application Protocol cont. wireless devices limited in power (batteries) compromised features; l l l small keypad/keyboard small display limited data storage standard IP cannot be used with mobile devices efficiently - in some cases not possible at all (800 x 600 page on a mobile in true colour)
WAP Cellular (GPRS, SMS) IP Packet Data Infrastructure WAP Gateway Provides translation between WAP and IP Applications: Banking, ebusiness, weather, news Internet
Bluetooth technology access to LAN 2. 4 GHz Licence-free laptop 1600 frequency hops per second cellular network mobile phone Low Tx power, low cost, battery operation mouse symmetric and assymetric connections printer laptop * replaces proprietary cables that connect devices together *
Establishing a connection two units within range can set up a connection (piconet) share a channel unit that initiates connection is master l other unit assumes role of slave any unit can be a master or a slave can only be one master in a piconet
Establishing a connection cont. before connection, each unit in standby l l scanning frequencies every 1. 28 secs keeps power demands low after initiation, full duty cycle implemented communicates using 2. 4 GHz wavelength l global compatibility two bands available; 23 channels and 79 channels l selected by software depending on geography
Bluetooth Applications automatic synchronisation of email, calendar, telephone book, smartcard data 3 -in-1 phone l l l home cordless phone - when in proximity of home base unit business cordless phone - use internal network conventional cellular phone cordless headset mobile computer conferencing automatic tolling - quite controversial!
WAP Technology Massive growth in Internet usage Rapid growth in mobile voice/data services Everyone has a mobile! Data transfer rates limited
Key features licence-free standard of adapting internet technology to meet wireless constraints Wireless Markup Language (WML) for authoring optimised protocol stack based on HTTP and TCP usable over a broad range of cellular data bearers
Architecture HTML Java. Script Wireless Application Environment (WAE) Wireless Session Protocol (WSP) WML used here HTTP Wireless Transaction Protocol (WTP) TLS SSL TCP/IP UDP/IP Wireless Transport Layer Security (WTLS) Wireless Diagram Protocol (WDP) User Datagram Protocol (UDP) Bearers: SMS, GPRS, 3 G etc.
Internet Model Web Server Client Web Browser HTTP Request (URL) CGI scripts etc. The Internet IP Stack HTTP Response (HTML) Internet Protocols HTML, Java. Script
WAP Model Client WAP user agents WAP Protocol stack Wireless Network WSP Request (URL) WSP Response (WML) WAP Protocol WAP Gateway Encode/ decode Protocol conversion Web Server HTTP Request (URL) CGI scripts etc. The Internet HTTP Response (WML) Internet Protocol WML, Java. Script
What’s so special about WAP? WML is binary encoded so compact over airwaves Extensive use of caching during sessions to minimise traffic Handles data requests asynchronously l avoids waiting for responses before handling next user request Designed to hold ‘long’ sessions l l l session resumed at last point if radio link fails WTP only sends broken packets of data TCP always sends entire message again
Wireless device issues Small display - WML structures docs in ‘decks’ and ‘cards’ card represents a single unit of interaction with user l deck is a service, represented by a collection of cards l well suited to small displays l Limited input - WML requires minimal keyboard functionality
Wireless device issues cont. Limited memory and CPU l WML is primarily text-based and requires a low hardware overhead Limited battery power l WAP transmissions minimised over air
Summary E-business currently utilises desktop technology Massive potential to open new mobile markets Bluetooth enables easy device connectivity, widening access to internet based services WAP is a protocol designed to address the limitations of wireless devices
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